The near field is used for which purpose?

The near field is used for which purpose?

• A. Used for diagnostic imaging
• B. Used for therapeutic purposes
• C. Not used
• D. For noise reduction

Answer: (B)

The near field is used for therapeutic purposes because this region allows the ultrasound energy to be concentrated into a small, intense focal zone deep within tissue. Therapeutic ultrasound relies on delivering high energy to a targeted spot to produce heating or mechanical effects, and the near-field/focused geometry of the beam enables precise energy deposition at that location while minimizing exposure to surrounding tissue. In contrast, diagnostic imaging aims for broader, lower-energy beams with safe, steady imaging conditions, which is why the near field isn’t the primary mode for imaging.

The near field is used for therapeutic purposes because this region allows the ultrasound energy to be concentrated into a small, intense focal zone deep within tissue. Therapeutic ultrasound relies on delivering high energy to a targeted spot to produce heating or mechanical effects, and the near-field/focused geometry of the beam enables precise energy deposition at that location while minimizing exposure to surrounding tissue. In contrast, diagnostic imaging aims for broader, lower-energy beams with safe, steady imaging conditions, which is why the near field isn’t the primary mode for imaging.